WO 97/07088 discloses a process for preparing olefins over boron beta zeolites. It is stated that the zeolites can be modified in order to increase, for example, the selectivity, the operating life or the number of possible regenerations. According to the disclosure, a possible modification of the hydroamination catalysts is to ion-exchange or dope the zeolites with alkali metals, such as Na and K, alkaline earth metals, such as Ca and Mg, earth metals, such as Tl, transition metals, such as Mn, Fe, Mo, Cu, Zn, Cr, noble metals and/or rare earth metals, such as La, Ce or Y. Doping with the element Li is not explicitly mentioned.